SES-1 is a geostationary communications satellite which is operated by SES World Skies, then by SES S.A. History It was originally ordered by SES Americom as a ground spare for AMC-5R, however in April 2008 a decision was made to launch it, and it was named AMC-1R. It was subsequently renamed AMC-4R, and finally SES-1 after SES Americom merged with SES New Skies to form SES World Skies. It was the third SES World Skies satellite to be launched following the merger, but the first to carry the new SES designation. SES-1 operates in geostationary orbit, and is intended to be located at a longitude of 101° West, where it will replace the AMC-2 and AMC-4 satellites, and be used broadcast high-definition television to very small aperture terminals in the United States. Spacecraft SES-1 was built by Orbital Sciences Corporation (OSC), and is based on the Star-2.4 satellite bus. It is equipped with 24 C-band, and 24 Ku-band transponders, and at launch it had a mass of . It has a design life of fifteen years, however it was launched with enough fuel to operate for at least sixteen years, if its systems are still functional. Launch The launch of SES-1 was conducted by International Launch Services (ILS), using a Proton-M launch vehicle with a Briz-M upper stage. The launch occurred from Site 200/39 at the Baikonur Cosmodrome, at 11:19:00 UTC on 24 April 2010. The launch successfully placed SES-1 into a subsynchronous orbit close to geostationary altitude. Mission In May and June 2010, SES-1 was positioned close to 131° West to temporarily provide backup to the AMC-11 satellite in the event that AMC-11 could not continue broadcasting whilst it is moved out of the way of the failed Galaxy 15 satellite, which passed close to it at the end of May 2010. In the end, services provided by AMC-11 were not interrupted. See also 2010 in spaceflight References Spacecraft launched in 2010 Communications satellites in geostationary orbit SES satellites Satellites using the GEOStar bus Satellites of Luxembourg